Locked safety joint



May 5, 1936.

H. P. wlcKERsHAM ET Al. 2,039,943

LOCKED SAFETY JOINT Filed July 1, 1935 F' /I 63,2 j /3 /5 l Jig lf3 (l 229 1 i .20 2 29 5V 1 15730 2/ 2/ 4"//"5f=.. 2a 23 27 JW/ 3 4 l/r A5 23 /3 5 :S 22 I ze /5 fVV/VTS.' 542% Maf/{ C'QSHAM n e 6 A /57 Zwaag;

ATTORNEY Patented May 5, 1936 PATENT OFFICE 2.039.943 j LocxEn SAFETY Jom'r Ham P. Wickersham and Harley J. Craig, Los Angeles, Calif.

Application July 1, 1935, Serial No. 29,203 1Q Claims. (Cl. Z55-28) This invention relates to well drilling tools and particularly pertains to a positive locked safety joint.

In the drilling of oil wells it is the usual practice to provide emergency means to insure that in the event the drill string and the tool carried thereby for any reason become fastened in the hole being drilled it will be possible to cause actuation of the emergency means to release the portion of the drill string below said means by counter rotation of the drill string so that the portion of the drill string above the point of release may be readily removed. In devices of this type, commonly known as safety joints, the construction usually contemplates that when the drill string and the joint are rotated in a clock- A f. se direction the joint will remain fastened, and

that when it is rotated inv a counterclockwise direction the parts of the joint may be releasedv and separated. In some instances it is highly desirable to maintain the safety joint in a locked condition, even upon counter rotation until it is desired to bring about a release, since such counter rotation might facilitate the loosening or dislodging of the fastened portion of the Ydrill string and its tool, and it is the principal object of the present invention to provide a safety joint for use in well drilling operations which joint is positively locked against separation by rotation in clockwise or counterclockwise direction until its release is desired by the operator who may then manipulate the drill string to cause the parts of the safety joint to assume positions with relation to each other which will allow them to separate upon counterrotation of the upper drill string section. l

The present invention contemplates the provision of a mandrel element carried on one section of the drill string, and a tubular element carried on the other section of the drill string, said elements being connected by an intermediate in'- ternally threaded sleeve carried upon the mandrel and splined to the tubular member.

The invention is illustrated by way of example in the accompanying drawing in which:

Figure 1 is a fragmentary view in section and elevation showing the safety joint attached to the drill string section.

Fig. 2 is an enlarged view in section and elevation showing the operative elements of the safety joint.

Fig. 3 is a view in transverse section through the safety joint as seen on the line 3-3 of Fig. 2 showing the locking splines.

Fig. 4 is a view in transverse section through the safety joint as seen on the line 4 4 of Fig. 2, showing the engagement of the locking sleeve with the tubular member.

Fig. 5 is a fragmentary view in section and elevation showing another form of the present in- 5 vention adapted to be released by a shear pin.

Referring more particularly to the drawing III indicates an upper drill string section fitted with a 4coupling II and a top sub I2. Threaded into the top sub I2 is a cylindrical mandrel I3 which 10 is formed with a fluid passageway Il through its center, the mandrel projecting into the tubular member I 5 of the safety joint. The tubular member I5 is connected with a lower sub I6 which in turn is suitably fitted with a coupling '15 I1 and a lower drill stem section I 8. It is desirable that the mandrel II3 and the sleeve I5 be normally held against rotation with relation to each other in clockwise and counterclockwise directions. This is brought about in the20 present case by locking splines III which project from sides of the mandrel Il and mesh normally with keyways 20 cut in the inner circumferential face of the tubular member I5. The length of the splines I9 agree substantially with the width of an internal shoulder 2I longitudinally through which the keyways 20 are cut. Below the shoulder 2I within the tubular member II is an enlarged bore 22. This bore is formed with longitudinally extending keyways 23 into which keys 24 carried by a lock sleeve 25 slide. The lock sleeve 2B is free to reciprocate within the bore 22 of the tubular member I5. It is held, however, in its uppermost position against Vthe under face of the annular shoulder 2I by an 35 expansion spring 26 which is disposed between the lower end face of the locking sleeve 25 and the upper face of sub I6. 'I'he length of the keyways 23 are such as to permit longitudinal shifting motion of the locking sleeve 25 within o .The mandrel I3 carries a wash pipe 29 which fits within a central passageway I4 of the mandrel and is packed by a suitable packing 20 and a packing gland 3|. The lower end of the mandrel is welded into the lower sub I6 and its upper 55 the tubular member I5 through which they extend, and the inner ends of which stand in an obstructing position with relation to the lock sleeve until suiiicient force has been applied upon the lock sleeve 25 by the mandrel Il to shear the pins, and allow disengagement of the splines IQ from their keyways 25 to tahe place. A relatively light spring s4 is used in the structure shown in Fig. 5 instead of the heavy spring 25 previously described. I'his light spring tends t0 hold the washer 32 in position.

In operation oi' the present invention the safety joint is assembled as shown in Fig. 2 of the drawing, and as lowered into the hole the spring 25 will maintain the tubular member I 5 in its lowermost position with relation to the mandrel Il and will also maintain the splines I9 in mesh with the keyways 20. In thevevent that the portion of the drill string I5 is in any manner caught in the hole the entire drill string may be rotated in a clockwise or counterclockwise direction and tension may be imposed upon the drill string tending t0 dislodge it. If this is not possible the tension is released from the drill string and a suiiicient amount of the drill string weight is-imposed upon the mandrel I3 to move the mandrel downwardly with relation to the relatively stationary tubular section I5. This downward movement is in opposition to the expansion of the spring 25 and continues until the upper ends of the splines Il have cleared the lower face of the shoulder 2 I Simultaneously with this downward movement the lock sleeve 25 will slide downwardly within the tubular member i5, it being held against rotation by the action oi the splines 23 and the keyways 2l. After the locking splines i 9 have moved to a point lower than the shoulder 2I and are therefore disengaged from their respective keyways a counterrotation of the upper drill string section I0 may be made. 'Ihis will cause the screw 21 of the mandrel Il to become unthreaded from the threaded A mandrelamitheinternalthreadsofthielock sleevell. J

Inbothoftbesedevicesitwillbeseenthatthe mandrels will be positively locked with relation the lock sleeve whereby the parts of the Joint may be held in assembled relation to each other.

2. A safety Joint comprising a tubular sleeve carried by one section of drill string, a mandrel carried by another section of drill string and telescoping into the sleeve, a lock sleeve slidably mounted within the tubular sleeve and splined thereto for limited longitudinal movement, a threaded connection between the mandrel and the lock sleeve whereby the parts of the joint may be held in assembled relation to each other, and means for temporarily and positively locking the mandrel and the tubular sleeve against rotation.

3. A safety joint comprising a tubular sleeve carried by one section of drill string, a mandrel carried by another section oi' drill string and telescoping into the sleeve, a lock sleeve siidably mounted within the tubular sleeve and splined thereto for limited longitudinal movement, a threaded connection between the mandrel and the lock sleeve whereby the parts of the joint may be held in assembled relation to each other, means for temporarily and positivelylocking the mandrel and the tubular sleeve against rotation, and means temporarily holding said positively locking means in their locked position.

4. A safety Joint comprising a tubular sleeve carried by one section of drill string, a mandrel carried by another section of drill string and telescoping into vthe sleeve, a lock sleeve slidably mounted within the tubular sleeve andsplined thereto for limited longitudinal movement, a threaded connection between the mandrel and the lock sleeve whereby the parts of the joint may be held in assembled relation to each other. means for temporarily and positively locking the mandrel and the tubular sleeve against rotation, and means temporarily holding said positively 4locking means in their locked position, said means including a spring acting between the tubular sleeve and the lock sleeve.

5. A safety joint comprising a tubular sleeve carried by one section of drill string, a mandrel carried by another section of drill string and telescoping thereinto. a lock sleeve mounted within the ytubular sleeve and splined thereto for longitudinal sliding movement, yieldable vmeans holding said lock sleeve in its outermost position with relation to said tubular sleeve and permitting the lock sleeve to be unscrewed from the and releasable means positively interlocking the mandrel with'the tubular sleeve to insure rotation of the mandrel and the sleeve in unison.

'1. A safety joint comprising a tubular sleeve carried upon one section of a drill string, a lock sleeve disposed within Ythe tubular sleeve and splined for longitudinal movement therein, a shoulder limiting the movement in one direction, a spring resisting movement in the other direction, a mandrel carried by another section of. drill string and threaded into said lock sleeve,

whereby the mandrel and lock sleeve may reciprocate in unison within the tubular sleeve between the said shoulder and against the resistance of said spring.

8. A safety joint comprising a tubular sleeve carried upon one section of a drill string, a lock sleeve disposed within the tubular sleeve and splined for longitudinal movement therein, a shoulder limiting the movement in one direction, a spring resisting movement in the other direction, a mandrel carried by another section of drill string and threaded into said lock sleeve, whereby the mandrel and lock sleeve may reciprocate in unison within the tubular sleeve between the said shoulder and against the resistance of said spring, said spring yieldably resisting an unscrewing motion of the lock sleeve with relation to the mandrel.

9. A safety joint comprising a tubular sleeve carried upon one section of a drill string, a look sleeve disposed within the tubular sleeve and splined for longitudinal movement therein, a shoulder limiting the movement in one direction, a spring resisting movement in the other direction, a mandrel carried by another section of drill string and threaded into said lock sleeve, whereby the mandrel and lock sleeve'may reciprocate in unison within the tubular sleeve between the lsaid shoulder and against the resistance of said spring, said spring yieldably resisting an unscrewing motion of the lock sleeve with relation to the mandrel, the splined connection between the mandrel and the tubular sleeve acting to hold the mandrel and the sleeve in a temporarily locked position with relation to each other for rotational movement in unison.

10. A safety joint comprising a tubular sleeve carried upon one section of drill string, a lock sleeve disposed within the tubular sleeve and splined for longitudinal sliding movement theree in, a shoulder limiting the outward movement of the lock sleeve with relation to the tubular sleeve. a mandrel carried by another section of drill string and threaded into said lock sleeve whereby the mandrel and the lock sleeve may reciprocate in unison within the tubular sleeve, spring means yieldably resisting said reciprocation in a downward direction, and yieldably resisting an unscrewing motion of the lock sleeve with relation to the mandrel, and a splined connection between the mandrel and the tubular sleeve whereby the mandrel and the sleeve may be held in a temporarily locked position with relation to each other for rotational movement in unison and will be released with relation to each other when the mandrel telescopes into the tubular sleeve.

HARLEY J. CRAIG. HARRY P. WICKERSHAM. 

